Little green Lamda electronic impending DOOM light has just come on

[bonnietiler]

Just driving along, car goes great by the way, and up pops the lamda light.. All Green it is..
What to do... Is it something and nothing..has the lamda sensor failed..is the cat knackered..
Who ... what...where..
Any help much appreciated
Bonnietiler

[stribo]

Get the codes read, could be lots of things.

[Ettienne]

Just driving along, car goes great by the way, and up pops the lamda light.. All Green it is..
What to do... Is it something and nothing..has the lamda sensor failed..is the cat knackered..
Who ... what...where..
Any help much appreciated
Bonnietiler

What car and mileage, most likely an air leak last 3 times I've had this it's been air leak, especially p1 / p2 s70 v70 etc

Check inlet manifold pipe work etc

[Doingitsideways]

Don't earlier (non obd2) 850s have the flash code reader on the strut tower?

If so, read them yourself and look the codes up

But I agree with the above, prob an air leak, or MAF is next likely suspect, lambda sensors don't tend to go out of whack too often.

Easy way to check all your inlet pipework is to leave it idling and spray something like carb cleaner around all the pipework and joints, especially the inlet manifold where it meets the head.
If the idle drops, you've found a leak

[Ettienne]

Don't earlier (non obd2) 850s have the flash code reader on the strut tower?

If so, read them yourself and look the codes up

But I agree with the above, prob an air leak, or MAF is next likely suspect, lambda sensors don't tend to go out of whack too often.

Easy way to check all your inlet pipework is to leave it idling and spray something like carb cleaner around all the pipework and joints, especially the inlet manifold where it meets the head.
If the idle drops, you've found a leak

I said this exact thing the other day, but if your spraying flammable spray idle should rise

[Doingitsideways]

Not necessarily, Steve.

It may be flammable, but prob nowhere near as much as petrol.
Every time I've sprayed carb cleaner into my inlets over the years, the engine bogs right down and you have to stop before it stalls.

It's probably more to do with the fact that it cocks the mixture up.